1. Field of the Invention
The present invention relates to a copolymer and a method for producing the same, and more particularly to a modified high cis butadiene-isoprene copolymer, a method for producing the same, and an application thereof.
2. Description of the Related Art
Conjugated diene polymer is widely used for resin modifying applications and various industrial goods, of which one is for manufacturing tires. Demands for low fuel consumption and wear loss for the tires have increased with increasing environmental consciousness in recent years. For conforming the demand trend, the rolling resistance property, the wet traction property, the tensile strength property, and etc. of mechanical characteristics of the conjugated diene polymer are very important.
Conjugated diene polymer having high content of cis-1,4 structure has good mechanical characteristics. Therefore are many conventional methods for manufacturing the conjugated diene polymer having high content of cis-1,4 structure. In those methods, catalysts formed of a combination of a metal compound, such as a Ni series compound, a Ti series compound, a Co series compound, a La series compound, etc., and an organic aluminum compound are usually used.
Currently, carbon black is added to conjugated diene polymer to increase the strength of the tires. In recent years, due to the depletion of oil resource and the global warming issue, many methods of replacing carbon black with silica as reinforcing filler have been provided. In comparison with carbon black, silica is more difficult to be uniformly distributed in conjugated diene polymer. Therefore, the compatibility between silica and conjugated diene polymer needs to be further increased. According to one improvement method, when adding silica to conjugated diene polymer during the manufacturing process of tires, a modifier is used for performing blending. However, since the blending uniformity largely affects the properties of the products, product quality may differ from batch to batch, and quality reproducibility is poor. Moreover, it is hard to make sure if the conjugated diene polymer is modified by the modifier, or the modifier only reacts with silica. Therefore, how to provide a conjugated diene polymer with silica well distributed therein and a method for manufacturing the same has become a prominent task for the industries.